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**Overview**• Importing data from generic raster files • Creating surfaces from point samples • Mapping contours • Calculating summary attributes for polygon features using a grid layer (“Zonal Statistics”) • Cross tabulating areas • "Querying" across multiple grid layers • Calculating neighborhood statistics • Calculating distance surfaces and buffers • Determining proximity • Converting raster and vector data sources**Overview**• Importing data from generic raster files • Creating surfaces from point samples • Mapping contours • Calculating summary attributes for polygon features using a grid layer (“Zonal statistics”) • Cross tabulating areas • "Querying" across multiple grid layers • Calculating neighborhood statistics • Calculating distance surfaces and buffers • Determining proximity • Converting raster and vector data sources**Importing data from generic raster files**• ArcGIS can import grids from 4 different generic raster data formats • ASCII raster file format • binary raster file format • USGS Digital Elevation Model (DEM) raster file format* • US DMA (Defense Mapping Agency) DTED (Digital Terrain Elevation Data) raster file format * common format; free for download from USGS**USGS source**Importing data from generic raster files • USGS DEMs are available online (free)**Overview**• Importing data from generic raster files • Creating surfaces from point samples • Mapping contours • Calculating summary attributes for polygon features using a grid layer (“Zonal statistics”) • Cross tabulating areas • "Querying" across multiple grid layers • Calculating neighborhood statistics • Calculating distance surfaces and buffers • Determining proximity • Converting raster and vector data sources**Creating surfaces from point samples**• Generation of a complete surface from incomplete point samples • Interpolation between and beyond individual sample points • Better estimation of surface value in locations near sample points • Several different interpolation methods available • Assumption of gradual change of value across landscape**Continuous surface**discrete sample points Creating surfaces from point samples • Points are interpolated to a surface**spline (minimized curvature)**• inverse distance weighting (local influence is strong) Creating surfaces from point samples • Two basic methods (spline and IDW)**Overview**• Importing data from generic raster files • Creating surfaces from point samples • Mapping contours • Calculating summary attributes for polygon features using a grid layer (“Zonal statistics”) • Cross tabulating areas • "Querying" across multiple grid layers • Calculating neighborhood statistics • Calculating distance surfaces and buffers • Determining proximity • Converting raster and vector data sources_**Mapping contours**• Finds adjacent cells of the same value • Converts linear arrangement of raster cells to vector lines • User control of base contour and contour interval • Few digitized contour line data sets exist for remote areas**new layer**Mapping contours • Group of contours created as shapefile**Overview**• Importing data from generic raster files • Creating surfaces from point samples • Mapping contours • Calculating summary attributes for polygon features using a grid layer (“Zonal statistics”) • Cross tabulating areas • "Querying" across multiple grid layers • Calculating neighborhood statistics • Calculating distance surfaces and buffers • Determining proximity • Converting raster and vector data sources**Summarizing zones**• Defines a zone of cells based on a group of integer cells or polygons with same value • Creates statistical summary of zone • Summary table is created • Summary chart**Summarizing zones**• “Zone” is a group of cells (or polygons) that have the same attribute value**Summarizing zones**• Table and chart are created statistics from input grid based on polygonal zones**Overview**• Importing data from generic raster files • Creating surfaces from point samples • Mapping contours • Calculating summary attributes for polygon features using a grid layer (“Zonal statistics”) • Cross tabulating areas • "Querying" across multiple grid layers • Calculating neighborhood statistics • Calculating distance surfaces and buffers • Determining proximity • Converting raster and vector data sources**Cross tabulating areas**• Creates a “zonal intersection” of integer grid layers (similar to vector intersection) • Output is a table • 1st input layer creates records (1 record for each unique value) • 2nd input layer creates fields (1 field for each unique value) • Table values are map unit area measurements of combinations of zones • Valuable technique for change detection**area measurementsin map units**Cross tabulating areas column layer (stands) • Output table row layer (soils)**Overview**• Importing data from generic raster files • Creating surfaces from point samples • Mapping contours • Calculating summary attributes for polygon features using a grid layer (“Zonal statistics”) • Cross tabulating areas • "Querying" across multiple grid layers • Calculating neighborhood statistics • Calculating distance surfaces and buffers • Determining proximity • Converting raster and vector data sources**"Querying" across multiple grid layers (“Map Query”)**• Raster Calculator is easy to use and gives rapid results • Results may be as good as vector overlay depending on cell size & relative precision • Multiple grids can be simultaneously queried(whereas only 2 vector layers can be compared in vector overlay) • Output represents cells that meet and do not meet query criteria**Overview**• Importing data from generic raster files • Creating surfaces from point samples • Mapping contours • Calculating summary attributes for polygon features using a grid layer (“Zonal statistics”) • Cross tabulating areas • "Querying" across multiple grid layers • Calculating neighborhood statistics • Calculating distance surfaces and buffers • Determining proximity • Converting raster and vector data sources**Calculating neighborhood statistics**• “Focal” statistical functions • Moving focus window calculates statistics for all cells within focus • Output value is written to central cell in output grid • Statistical functions: • Minimum • Maximum • Mean • Median • Sum • Range • Standard Deviation • Majority • Minority • Variety**Calculating neighborhood statistics**locations of greatest variationin elevation • Focal Standard Deviation**Calculating neighborhood statistics: high pass filter**• High-pass filter (focal process)**Calculating neighborhood statistics: high pass filter**edges are higher or in absolute value • High-pass filter finds edges**Overview**• Importing data from generic raster files • Creating surfaces from point samples • Mapping contours • Calculating summary attributes for polygon features using a grid layer (“Zonal statistics”) • Cross tabulating areas • "Querying" across multiple grid layers • Calculating neighborhood statistics • Calculating distance surfaces and buffers • Determining proximity • Converting raster and vector data sources**Calculating distance surfaces and buffers**• Similar to buffering with vector data • Creates a continuous distance surfacerather than a discrete bounded polygonal area • Distance measured from input layer featuresor grid cells**continuous distance value surface**Calculating distance surfaces and buffers • Distance from vector features**Overview**• Importing data from generic raster files • Creating surfaces from point samples • Mapping contours • Calculating summary attributes for polygon features using a grid layer (“Zonal statistics”) • Cross tabulating areas • "Querying" across multiple grid layers • Calculating neighborhood statistics • Calculating distance surfaces and buffers • Determining proximity • Converting raster and vector data sources**Assigning proximity**• “what territories are closest to a set of features?” • output cells have the value of the closest input feature “Thiessen,” “Voronoi”**Overview**• Importing data from generic raster files • Creating surfaces from point samples • Mapping contours • Calculating summary attributes for polygon features using a grid layer (“Zonal statistics”) • Cross tabulating areas • "Querying" across multiple grid layers • Calculating neighborhood statistics • Calculating distance surfaces and buffers • Determining proximity • Converting raster and vector data sources**Converting raster and vector data sources**• Raster vector conversions are possible • Always a loss or generalization of shape • Support for point, line, polygon grid in ArcGIS • Avoid converting grids that do not have large contiguous zones (e.g., DEMs)**polygon shapefile**Converting raster and vector data sources: grid to polygon • Convert grid zones to polygon shapefile**GRIDCODEfield**Converting raster and vector data sources: grid to polygon • Convert grid zones to polygon shapefile**Value field**Converting raster and vector data sources: grid to polygon • Convert vector lines to grid zones